CRITIQUE WAYS IN WHICH DATA IS PRESENTED

Main Resource: Statistics Canada Website

INFORMATION: USE IN SOCIETY You have probably heard of the term the

information age. It describes how modern society depends on information as a resource. People rely on information to make decisions and recommendations in many fields, including politics, economics, environment and entertainment.

Without reliable information, people can make poor decisions that sometimes result in serious consequences.

WHY WE NEED TO BE CRITICAL Since the media plays an immense part in our

daily life and they are continually giving us information (data).

Data analysis is often used in advertising, forecasting, and public policy. The media is full of representations of data (i.e. Graphs or tables) to support statistical claims.

We need to be critical to: Know what is relevant Know what is important Know what is true Know what is biased Identify misinformation Etc.

WHAT IS A GRAPH? A graph is a visual representation of a

relationship between, but not restricted to, two variables.

Graphs are effective visual tools because they present information quickly and easily. It is not surprising then, that graphs are commonly used by print and electronic media.

DIFFERENT TYPE OF GRAPHS Circle graphs Line graphs Bar graphs Double bar graphs Pictographs

CIRCLE GRAPHS (PIE CHARTS) A circle graph displays data as a

percentage of the whole. Each pie section should have a label and percentage. A total data number should be included.

LINE GRAPHS A line graph plots continuous data as

points and then joins them with a line. Multiple data sets can be graphed together, but a key must be used.

BAR GRAPHS AND DOUBLE BAR GRAPHS A bar graph displays discrete data in

separate columns. A double bar graph can be used to compare two data sets. Categories are considered unordered and can be rearranged alphabetically, by size, etc.

PICTOGRAPHS A pictograph uses an icon to represent a

quantity of data values in order to decrease the size of the graph. A key must be used to explain the icon.

MISINTERPRETATION OF INFORMATION Misinterpretation is a common problem

when using statistical information. It may be caused by a number of factors.

Misunderstanding the dataUsing incomparable definitionsDeliberately misinterpreting the information

ACTIVITY In groups of 2 or 3, come get a

worksheet and answer the questions. You will need to prepare a short

presentation about your topic (based on your worksheet) to present to the class.

CIRCLE GRAPHS (PIE CHARTS) Advantages

Visually appealing Shows percent of total for each category

Disadvantages No exact numerical data Hard to compare 2 data sets "Other" category can be a problem Total unknown unless specified Best for 3 to 7 categories Use only with discrete data

LINE GRAPHS Advantages

Can compare multiple continuous data sets easily

Interim data can be inferred from graph line Disadvantages

Use only with continuous data

BAR GRAPHS AND DOUBLE BAR GRPAHS Advantages

Visually strong Can easily compare two or three data sets

Disadvantages Graph categories can be reordered to

emphasize certain effects Use only with discrete data

PICTOGRAPHS Advantages

Easy to read Visually appealing Handles large data sets easily using keyed

icons Disadvantages

Hard to quantify partial icons Icons must be of consistent size Best for only 2-6 categories Very simplistic

DELIBERATELY MISINTERPRETING INFORMATION

Look at the effect of not starting the y-axis of 0.

It is important to start graphs at 0.

DELIBERATELY MISINTERPRETING INFORMATION

Look at this pictograph. It looks like there are more horses. It is important that all the pictures are the same size.

DELIBERATELY MISINTERPRETING INFORMATION

Why does Graph A look different than Graph B? Both the graphs represent the same data.

DELIBERATELY MISINTERPRETING INFORMATION

The graphs look different due to the different vertical scales. Graph A appears to show a more rapid decrease in sales than graph B.